Description: The aims of the Environmental Science and Engineering Scientific Core are: 1) To develop new methods to measure environmental contaminants; 2) to characterize hazard exposures of populations; 3) to develop and apply new techniques to estimate dose to target tissues; and 4) to participate in exposure-response studies for both humans and lab animals. This scientific core has been particularly productive, with over 200 peer reviewed papers. The focus is on the assessment of human exposure to environmental contaminants, and the researchers have developed methods to measure exposures that were not previously available, and they have evaluated exposures of populations in several settings to diverse air contaminants. The seven faculty members in the core present a good balance of emphasis on occupational exposures and environmental exposures, with detailed emphases on aerosols and biological agents. Future work includes the development of screening methods for environmental estrogens, refinement of the particle and ozone samplers developed already, a new GC-MS method for identifying and quantifying environmental microorganisms, analysis of water samples from the Harvard Nurses Health Study to determine if metals and chemicals in the water are associated with diseases in nurses, studies of occupational exposures of petrochemical workers in China and boiler repair workers in the United States, laboratory exposures of volunteers to 1,3 butadiene to determine human metabolic rates in order to refine a physiologic-pharmacokinetic model of exposure and metabolism, development of methods for breath, blood and saliva sampling to quantify uptake of butadiene, and development of DNA adducts as exposure markers of PAHs for roofers and pavers working with asphalt. Much of this work is being done in collaboration with members of other scientific cores.